Incorporation of particles, particularly metallic flake, into powder coatings can be difficult. Such particles are typically either extruded with the other components of the powder coating, or post-added to a coating after extrusion. Passing these particles through an extruder, however, can result in a loss of appearance or other characteristics and can alter the size and/or shape of the particles. For example, if metallic flake is extruded with the other components of a powder coating, the flake will become distorted and will also lose at least some of its luster as a result of the extrusion process. Post-addition of metallic flake can also cause problems, particularly when applying the powder coating by electrostatic spray; the metallic flake can pick up a charge differently than the other pigments or coating components, which can cause “picture framing” of the metallic flake. Use of particles that are bonded to the powder coating also has drawbacks; the bonding process is expensive and requires special equipment.
Accordingly, there remains a need for particles that can be successfully incorporated into powder coatings without altering the size and/or shape of the particles or diminishing the desired effect achieved by the particles.